Patient positioning systems are used for the accurate and reproducible positioning of patients for radiation therapy, diagnostic imaging, surgery and other medical procedures. For modern radiotherapy treatments, precise positioning of the patient is an indispensable prerequisite.
Typically, such positioning systems use a mouldable vacuum cushion in order to combine patient comfort with reproducible accuracy of the patient's position. The vacuum cushion consists of a hull material, typically a nylon cloth laminated with a polyurethane coating, a filling material such as polystyrene grains, and a valve.
In order to form the cushion into a mould, the patient is placed on the vacuum cushion which then deforms to a shape that accommodates the patient. The tube is that connected to a vacuum supply such as one from a vacuum pump. This generates a vacuum in the cushion, and the vacuum cushion is moulded to the patient's contours. The grains that were previously free-flowing are constrained by compression resulting from the atmospheric pressure on the outside of the cushion.
Typical characteristics of such cushions include                reproducible positioning of the patient from imaging to treatment and subsequent treatment fractions, while preserving patient comfort and improving the clinical workflow        optimisation of clinical workflow for a range of clinical setups and indications such as thorax, hip, full body and head and neck        a comfortable, stable and precise mould of the patient's position        
Such vacuum cushions are typically constructed entirely of radio translucent materials to provide consistent artefact-free image clarity with minimal dose attenuation.
A coated nylon material for the exterior of the cushion enables smooth mould definition, comfortable patient positioning and ease of cleaning.